DOCUMENT:Q161286 14-JUL-1997 [vbwin] TITLE :HOWTO: Use a Common Dialog File Open Dialog with Win32 API PRODUCT :Microsoft Visual Basic for Windows PROD/VER:4.0 5.0 OPER/SYS:WINDOWS KEYWORDS:kbusage VB432 VB4Win vb5all vb5howto VBKBCommonDialog kbhowto ====================================================================== --------------------------------------------------------------------- The information in this article applies to: - Microsoft Visual Basic Professional and Enterprise Editions, for Windows, version 5.0 - Standard, Professional, and Enterprise Editions of Microsoft Visual Basic, 32-bit only, for Windows, version 4.0 --------------------------------------------------------------------- SUMMARY ======= This article provides a code sample and demonstrates how to use the File Open dialog box in the Comdlg32.dll. Making use of Comdlg32.OCX is a good reuse of resources under Windows, because Windows always has its dependent file, Comdlg32.dll, loaded. It provides an easy-to-use interface, but can be a performance hit. If you use the OCX control, you have to load the module into memory and also distribute a 90K OCX control to users of your software. To improve performance, you should minimize the use of controls in your applications. Instead, you can use the Win32 API calls directly. If you use the API calls, you may lose some of the functionality that Comdlg32.OCX offers, such as the Help button. If you require the Help button, you will need to use the Comdlg32.OCX control. MORE INFORMATION ================ Step-by-Step Example -------------------- 1. Start Visual Basic 5.0 and select Standard EXE. If Visual Basic 5.0 is already running, click New Project on the File menu and select Standard EXE. Form1 is created by default. 2. Place a CommandButton on Form1. 3. Add the following code to the Form1 code window: Option Explicit Private Declare Function GetOpenFileName Lib "comdlg32.dll" Alias _ "GetOpenFileNameA" (pOpenfilename As OPENFILENAME) As Long Private Type OPENFILENAME lStructSize As Long hwndOwner As Long hInstance As Long lpstrFilter As String lpstrCustomFilter As String nMaxCustFilter As Long nFilterIndex As Long lpstrFile As String nMaxFile As Long lpstrFileTitle As String nMaxFileTitle As Long lpstrInitialDir As String lpstrTitle As String flags As Long nFileOffset As Integer nFileExtension As Integer lpstrDefExt As String lCustData As Long lpfnHook As Long lpTemplateName As String End Type Private Sub Command1_Click() Dim OpenFile As OPENFILENAME Dim lReturn As Long Dim sFilter As String OpenFile.lStructSize = Len(OpenFile) OpenFile.hwndOwner = Form1.hWnd OpenFile.hInstance = App.hInstance sFilter = "Batch Files (*.bat)" & Chr(0) & "*.BAT" & Chr(0) OpenFile.lpstrFilter = sFilter OpenFile.nFilterIndex = 1 OpenFile.lpstrFile = String(257, 0) OpenFile.nMaxFile = Len(OpenFile.lpstrFile) - 1 OpenFile.lpstrFileTitle = OpenFile.lpstrFile OpenFile.nMaxFileTitle = OpenFile.nMaxFile OpenFile.lpstrInitialDir = "C:\" OpenFile.lpstrTitle = "Use the Comdlg API not the OCX" OpenFile.flags = 0 lReturn = GetOpenFileName(OpenFile) If lReturn = 0 Then MsgBox "The User pressed the Cancel Button" Else MsgBox "The user Chose " & Trim(OpenFile.lpstrFile) End If End Sub 4. Press the F5 key to run the project, and click the CommandButton. You should see the File Open dialog box appear with the options set. REFERENCES ========== The Win32 SDK documents other calls to the Comdlg32.dll such as ChooseColor, ChooseFont, and GetSaveFileName. For more information, please see the following articles in the Microsoft Knowledge Base: ARTICLE ID: Q106682 TITLE : Default Extension Ignores File Type in VB Common Dialog ARTICLE ID: Q137194 TITLE : GetOpenFileName nMaxFile Interpreted Incorrectly ====================================================================== Keywords : kbusage VB432 VB4Win vb5all vb5howto VBKBCommonDialog kbhowto Version : 4.0 5.0 Platform : WINDOWS Issue type : kbhowto ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 1997.